Are the allies always good guys?
I spotted that when a war is described in English, the side described as "allies" is nearly always reserved to the side to which the speaker has sympathy. Although technically the word means somebody in alliance, I virtually never seen the word applied to a supposedly bad side even if that side has an alliance of their own.
It seems this sometimes can be used to point a "good" side in a conflict when commenting the news (even if no Western power is directly involved).
I also noticed that regarding WWII some commenters often say "the Allies and the Soviets" or "the Allies decided to make offensive after that of the Soviets" even though technically the USSR was allied with say Britain and the USA. Instances where the Soviets are grouped into "Allies" are rare especially after the fall of the USSR. Does this usage indicate the commenter's anti-Soviet or anti-Communist inclination?
I also once spotted the usage of the word in regards of the Crimean war between Great Britain and the Russian Empire in the 19th century where British allies (i.e. Turks) were called "the allies". Does such usage also indicate that the author is sympathetic to the British and Turkish side?
Another explanation may be that the word can be simply used to refer any side that is allied with the country from which the speaker originates (i.e. UK and/or the USA in most cases for an English speaker) and as such the speaker is most likely support that side and expresses sympathy to it.
Solution 1:
Since the USSR was part of the Allied States after June 1941, it's reasonable to say there is some bias involved if they weren't included as part of the Allied Powers in a discussion of WWII. However, the Soviets did invade Poland and Finland before joining the Allies, so technically there may be WWII descriptions which correctly make distinctions between actions of the Allies and Soviets.
The Allies of WWII were countries that opposed the Axis Powers.
Using the lower-case allies when describing alliances between nations makes no distinction does not, in my opinion, indicate any bias on the part of the speaker. For example, you could speak interchangeably between the USSR and her allies and the USA and her allies during the Cold War without showing bias either way.
So the answer to the question Are allies always good guys? is no.
Solution 2:
In World War II, the two sides are referred to in English as the Allied Powers (US, Britain, etc.) and the Axis Powers (Germany, Japan, etc.), often shortened to the Allies and the Axis.
A British speaker during World War II could correctly have referred to "Germany's allies". It's just that when speaking of allies without further restriction, the assumption is that you're referring to your own allies.
It would be odd to fail to include the USSR in the grouping of "the Allies" in the context of World War II. I'd like to see the context on that in order to answer it better.